Overall prevalence of samples showing evidence of any PI resistance decreased gradually over time (from 2003 to 2009: 47.0% to 32.2% [VTY lower CCO]; 49.1% to 42.2% [US-FDA mutation list]. Mean prevalence of each of the 11 individual DRV RAMs also decreased over time (Figure 1)

Prevalence of samples harbouring &ge;1 DRV RAMs also decreased over time. In 2009, 94.3% of all samples harboured zero DRV RAMs versus 85.3% in 2003. Among samples with evidence of PI resistance, 88% vs 72% (per FDA list) and 84% vs 70% (to any PI defined by predicted FC&gt; low CCO) harboured zero DRV RAMs. The most common three DRV RAM combination was L33F,I54L,I84V which was detected with a prevalence of 0.15% in 2003 and 0.08% in 2009.

Overall prevalence of samples showing evidence of any PI resistance decreased gradually over time (from 2003 to 2009: 47.0% to 32.2% [VTY lower CCO]; 49.1% to 42.2% [US-FDA mutation list]. Mean prevalence of each of the 11 individual DRV RAMs also decreased over time (Figure 1)

Prevalence of samples harbouring &ge;1 DRV RAMs also decreased over time. In 2009, 94.3% of all samples harboured zero DRV RAMs versus 85.3% in 2003. Among samples with evidence of PI resistance, 88% vs 72% (per FDA list) and 84% vs 70% (to any PI defined by predicted FC&gt; low CCO) harboured zero DRV RAMs. The most common three DRV RAM combination was L33F,I54L,I84V which was detected with a prevalence of 0.15% in 2003 and 0.08% in 2009.